Electrosurgical forceps are well known in the medical arts. For example, an electrosurgical endoscopic forceps is utilized in surgical procedures, e.g., laparoscopic surgical procedure, where access to tissue is accomplished through a cannula or other suitable device positioned in an opening on a patient. The endoscopic forceps, typically, includes a housing; a handle assembly including a movable handle; a drive assembly; a shaft; a cutting mechanism such as, for example, a knife blade assembly; and an end effector assembly attached to a distal end of the shaft. The end effector includes jaw members that operably communicate with the drive assembly to manipulate tissue, e.g., grasp and seal tissue. Typically, the endoscopic forceps utilizes both mechanical clamping action and electrical energy to effect hemostasis by heating the tissue and blood vessels to coagulate, cauterize, seal, cut, desiccate, and/or fulgurate tissue. Typically, subsequent to effecting hemostasis, a knife blade of the knife blade assembly is deployed to sever the effected tissue.
Conventional endoscopic forceps, typically, utilize a safety blade lockout mechanism that prevents the blade from being unintentionally deployed. In particular, an endoscopic forceps may be configured to utilize a direct interaction between a lever and a trigger (or via another linkage in the lever mechanism) on the handle assembly to prevent the knife blade from being unintentionally deployed. That is, the knife blade is prevented from moving or translating into a knife slot on one or both of the jaw members. Under certain surgical scenarios, however, such as, for example, when the lever is in a “latched” configuration (i.e., the knife blade is operable to sever tissue) and a thick bundle of tissue is positioned between the jaw members, there exists a possibility of the knife blade deploying and wandering or drifting out of the knife slot(s) on the jaw member(s) and becoming trapped between the jaw members when they are moved to the clamping configuration. This condition is commonly referred to in the art as “blade trap.” As can be appreciated, “blade trap” may cause a cutting edge of the knife blade to ineffectively sever electrosurgically treated tissue, i.e., the knife blade may not fully or “swiftly” sever the electrosurgically treated tissue.